Method and device for inputting coordinate-position and a display board system

ABSTRACT

The coordinate-position input device has a frame with a reflecting member for recursively reflecting light provided in an inner side from four edges of the frame forming a rectangular form. Two optical units irradiate light to the reflecting members and receive the reflected light. With the mounting member(s) the frame can be detachably attached to a white board. The two optical units are located at both ends of any one of frame edges forming the frame, and at the same time the two optical units and the frame body are integrated to each other.

FIELD OF THE INVENTION

The present invention relates to a method and device for inputting acoordinate position. A touch-panel surface is formed by irradiatinglight on the surface of a white board or a display unit which light issubstantially parallel to the surface and a position on the surface ofthe white board or the display unit is inputted by detecting a positionon the surface where the light forming the touch-panel surface isblocked. More particularly the invention relates to a device forinputting coordinate position in which can be detachably attached to thewriting surface of a white board or display surface of a display unit.The present invention also relates to a display board system which usesthe coordinate-position input device for inputting a manually specifiedposition as the coordinate position.

BACKGROUND OF THE INVENTION

When a white board (or a blackboard) is used in a meeting or deliveringa lecture in a school or a college or the like, in order to record thecontents written on the white board it has been general to copy thecontents into a notebook by hand or to input the contents in some memoryusing a word processor or the like. In recent years, in association withthe widespread use of digital cameras or the like, there has also beenemployed a method of recording the contents written on a white board byphotographing the contents.

A display board device with a scanner and a printer provided to a whiteboard is becoming popular. In such a device, contents written on thewhite board are scanned and read, and the read contents can directly beprinted (recorded) onto a paper with the help of the printer.

Further, there has been also proposed a display board system having alarge display unit such as a plasma display, a coordinate-position inputdevice and a control unit for controlling these components. Thecoordinate-position input device forms a touch-panel surface on thedisplay surface of the display unit. Information (coordinate position)is input into the coordinate-position input device instead of directlywriting on the white board. The information input into thecoordinate-position input device is displayed onto the display surfaceof the display unit and the information can be stored in a storingdevice such as a memory as well.

As a method of detecting a coordinate position by thecoordinate-position input device provided in this type of electronicblackboard device, there is a method of irradiating light onto theentire surface provided in a coordinate position input area anddetecting a position of a pen on this surface by detecting the reflectedlight. Such a method is disclosed in Japanese Patent Laid-OpenPublication No. HEI 9-91094. Disclosed in this Japanese Patent Laid-OpenPublication No. HEI 9-91094 is a device which scans light so as toirradiate the light onto the entire surface by driving a light sourcewith the help of a driving unit.

There is now a device having a further simplified structure in which thedriving unit from the device described above is eliminated. In such adevice, the light emitted from a light source is spread in a fan shapewith the help of a lens or the like so that the ight is spread over theentire area of the writing surface. FIG. 23 explains the principles ofthis type of method in a simple maimer. The device shown in the figurehas a panel 80 as a writing surface. Reflecting members 2 are providedon three sides of the panel 80. A light source R is provided at a cornerin the lower right side thereof in the figure, and a light source L isprovided at a corner in the lower left side thereof It should be notedthat a point P(x_(p), y_(p)) on the panel 80 shows a position of a tipof a pen thereon.

In the structure shown in the figure, light beams emitted from the lightsource R and the light source L are spread by lenses (not shown herein)located in the front section of the light sources R and L respectively,and each of the spread light becomes a flux of light (a fan-shaped lightflux) having a fan shape with a central angle of 90 degreesrespectively. The fan-shaped light flux is reflected by the reflectingmembers 2 provided on the three sides of the panel 80, the reflectingmembers 2 are so designed that the fan-shaped light flux is reflectedtherefrom along the optical path which is same as at the time of itsemission. Therefore, the reflected fan-shaped light fluxes travel in thedirection of the light sources r and L along the same optical path as atthe time of their emission. Further, for instance, each of the lightfluxes is directed towards a light receiving section (not shown herein)by a mirror (not shown herein) provided on the optical path and detectedtherein.

With such a structure as described above, when the tip of a pen ispresent at the position of the point P on the panel 80, some lightpassing through the point P of the fan-shaped light flux is reflected bythe pen tip and can not reach the reflecting members 2 (this state isdescribed in the following specification as a state in which the lightis blocked by a pen tip). Because of that, only the reflected light ofthe light passing through the point P of the fan-shaped light flux cannot resultantly be detected by the light receiving section. At thispoint, if a CCD line sensor is used as a light receiving section, forinstance, the optical axis of the light not having been received can beidentified from the entire reflected light.

It is known that the optical axis of the reflected light is identical tothat of the emitted light and that the point P is present on the opticalaxis of the light which has not been detected, so that the angle ofemission of the light passing through the point P can be computed fromthe optical axis of the reflected light which has not been detected.Accordingly, emission angles θ_(L) and θ_(R) are obtained from theresults of light reception by the two light receiving sections, andoptical axis a_(L) and optical axis a_(R) can be obtained from these twoemission angles respectively. Further, the coordinates (x_(p), y_(p)) ofthe point P can be computed as a point of intersection of those opticalaxis a_(L) and optical axis a_(R).

More specifically, the coordinates (x_(p), y_(p)) of the point P areobtained as described below. Namely,

x _(p)−(W·tan θ_(R))/(tan θ_(L)+tan θ_(R))  (1)

$\begin{matrix}{y_{P} = {{\left( {\tan \quad {\theta_{L} \cdot W \cdot \tan}\quad \theta_{R}} \right)/\left( {{\tan \quad \theta_{L}} + {\tan \quad \theta_{R}}} \right)}\quad = {{x_{p} \cdot \tan}\quad \theta_{L}}}} & (2)\end{matrix}$

Where W is a distance between the centers of the light source R andlight source L.

With the method described above, the coordinate-position input devicedescribed above can automatically record the contents written on thepanel 80 by reading the locus of a pen tip by means of successivelyreading the coordinate positions of the pen tip moving along the panel80.

In the conventional technology, however, there are problems as describedbelow when contents written on a white board is recorded.

In order to record the contents written on a white board, it is requiredto copy the contents into a notebook by hand or to input the contentswith the help of a word processor or the like, so that work by hand isessential in both of the cases. The copying work (copying the contentsinto a notebook) or the inputting work (inputting the contents into aword processor) is troublesome, inconvenient and thereforedisadvantageous.

Secondly, when contents written on a white board are recorded byphotographing it with a digital camera or the like, the contents have tobe photographed at a location some distance from the board so that theentire white board can be viewed through the viewfinder of the camera.When a photograph is taken from a distance, information written on thewhite board with the small characters is hard to be interpreted fromsuch a photograph.

On the other hand, the conventional display board device or theconventional display board system has problems as described below.

Although the information on a white board can easily be recorded byscanning the surface of a white board with a scanner and then printingthe information onto a paper by using a printer, in this case, themethod is realized based on the condition that a display board devicewith a white board, a scanner, and a printer integrated together isused. With such a configuration, there is a disadvantage that thedisplay board device become very expensive.

Secondly, since the display board device or the display board system isused together with one particular white board or an integrated boardwith a display unit incorporated in the device or the system, in otherwords, the display board device or the display board system is notdesigned for general purpose use. For example, such a system can not beused with a white board or a display unit other than the specific whiteboard or the display unit. Thus, the conventional type of the device orsystem has not been capable of solving the problems coming up whencontents written on a white board or a display unit each generally usedas a discrete device are recorded.

Further the conventional type of coordinate-position input device hasproblems as described below.

When a coordinate-position input device having a touch-panel surface orthe like and a display unit which are not previously integrated to eachother, the display surface of the display unit is difficult to be usedas a touch-panel surface. A coordinate-position input device which caneasily be mountable onto the display surface of a display unit has notbeen proposed.

Secondly, emission angles θ_(R) and θ_(L) obtained by the method used inthe-conventional type of coordinate-position input device depend on theangle (attached angle) at which the light source R and the light sourceL are attached to the panel 80. Therefore, the coordinates of the pointP computed from the emission angles θ_(R) and θ_(L) also vary inassociation with the attached angles. If the attached angles are notwhat they actually should be, then there is a disadvantage that theposition of a pen tip can not accurately be read, which results in thefact that the written contents can not accurately be recorded.

A concrete method for computing the emission angles is described below.

FIG. 24 shows a relation between the emission angle θ_(L), the lightsource L and the attached angle β_(L) of the light source L when theemission angle θ_(L) is obtained. It should be noted that while FIG. 24explains the case for the light source L, the attached angle β_(R) ofthe light source R can be obtained in a similar manner as describedhere.

In FIG. 24, an axis as indicated by a phantom line is an optical axispassing through the center of light emitted from the light source L.Herein, a CCD line sensor c as a light receiving section is so providedthat the light having the axis a_(s) as its optical axis is received byan element positioning at the center o of the sensor. It is assumed thatthe angle between an axis (described 0-axis in the figure) parallel tothe lower edge of the panel 80 and the axis a_(s) is the attached angleβ_(L). It is also assumed that a distance between the light source L andthe center o of the CCD line sensor c is t, and further a distancebetween the CCD element which has detected a blockage such as due to apen tip and the center o thereof is a.

In the example shown in FIG. 24 for obtaining the emission angle θ_(L),at first, an angle as a difference between the attached angle β_(L) andthe emission angle θ_(L) is α_(L), and then this angle α_(L) is obtainedfrom the equation described below.

tan α_(L) =a/t  (4)

Then, the emission angle is obtained by the equation described belowfrom the obtained angle α_(L).

θ_(L)=β_(L)−α_(L)  (5)

As described above, it is clear that, when the actual attached angle ofthe light source L with respect to the CCD line sensor c is displacedfrom the attached angle β_(L) used in equation (5), the value of θ_(L)will be inaccurate and the coordinates (x_(p), y_(p)) of point Pcomputed according to the value θ_(L) will also be inaccurate.

It is required, in order to prevent the location of a blockage from itsbeing sensed inaccurately due to displacement of the attache dangle,that precision of attaching a light receiving section such as a CCD linesensor or a light to the device is mechanically enhanced or thatadjustment precision after attachment thereof is enhanced. However, muchof the technology described above requires guesswork and experience ofskilled engineers, and because of that, it has been thought to begenerally inappropriate that this technology is applied to productsmass-produced.

SUMMARY OF THE INVENTION

It is a first object of the present invention to enable, for the purposeof solving the problems described above, recording of contents writtenon a white board easily and readably without using the hands as well asto provide general versatility applicable to an ordinary white board.

It is a second object of the present invention to provide acoordinate-position input device usable by easily mounting on a displaysurface of a display unit with high general versatility.

It is a third object of the present invention to provide acoordinate-position input device attachable with higher precision ascompared to a light receiving section and a light source as well as toprovide a display board system using this coordinate-position inputdevice.

Further, it is a fourth object of the present invention to provide acoordinate-position input device which can accurately computedisplacement of an attached angle and accurately read written contentsby easily correcting this displacement as well as to provide a displayboard system using this coordinate-position input device.

With the present invention, a frame body having two optical unitsintegrated in it is detachably attached to a writing surface of a whiteboard or a display surface of a display unit by utilizing mountingmembers. Further, a touch-panel surface is formed on the writing surfaceor the display surface by using the two optical units as well asreflecting members located in the frame body and a position where thelight that forms the touch-panel surface is blocked is detected. Thus itbecomes possible to input a coordinate position on the writing surfaceor the display surface.

With the present invention, it is possible to input a coordinateposition, by detachably attaching a frame body to a writing surface of awhite board or a display surface of a display unit using mountingmembers, further attaching two optical units to the frame body to adjusteach irradiating direction of light therefrom, forming a touch-panelsurface with the two optical units as well as reflecting members locatedin the frame body and detecting a position where the light for formingthe touch-panel surface is blocked, on the write-in surface or thedisplay surface thereof.

With the present invention, a computing section computes a coordinateposition of a blocked point on the writing surface or the displaysurface from a direction of reflected light not received by lightreceiving sections of the two optical units as well as from a distancebetween the light receiving sections thereof, so that a coordinateposition of the blocked point can be outputted from thecoordinate-position input device.

With the present invention, when a coordinate-position input mode and aninput suspend mode are exclusively specified by a specifying unit, acontrol unit provides controls over the two optical units and/or thecomputing section according to the specified mode, which allows the userto freely select either the case where a coordinate position is inputtedthrough the touch-panel surface or the case where a coordinate positionis not inputted.

With the present invention, the frame body can be attached in any of thelongitudinal direction and the lateral direction, which allowsflexibility for attaching the frame body to a writing surface of a whiteboard or a display surface of a display unit to be enhanced.

With the present invention, a mounting member is made with any of amagnet, a hook, a form enabling hanging, a suction cup, a face-typefastener, an engaging form, and an adhesive or a combination thereof,which allows the device of the invention to be attached to the whiteboard or display unit with its simple structure.

With the present invention, each edge of the frame is extendable inmulti-steps by an adjustment mechanism, and the reflecting member iswound into a roll inside the adjustment mechanism when the frame iscontracted, so that the frame body may be contracted when it is to becarried or extended when it is to be used, which allows itstransportability to be enhanced.

With the present invention, each edge of the frame is extendable inmulti-steps by an adjustment mechanism, and the reflecting member isalso extendable in multi-steps together with the frame edge, so that theframe body may be contracted when it is to be carried or extended whenit is to be used, which allows its transportability to be enhanced.

With the present invention, the coordinate position of obstacle can bestored in a storing section.

With the present invention, the coordinate position of the obstacle canbe stored in an external memory, and the stored contents can easily beaccessed by utilizing some other equipment by attaching the externalmemory thereto.

With the present invention, the coordinate position of the obstacle canbe stored on a frame memory.

With the present invention, even when a light emitting unit and a lightdetecting unit are attached to or detached from an area defining member,a positional relation between the light emitting unit and the lightdetecting unit can be maintained to be constant at any time.

With the present invention, even when a light emitting unit and a lightdetecting unit are attached to or detached from an area defining member,a positional relation between the light emitting unit and the lightdetecting unit can be maintained to be constant at any time, and inaddition the state of emission and detection can also be maintained tobe constant at any time.

With the present invention, the precision of alignment between anoptical unit and an area defining member can comparatively easily beenhanced.

With the present invention, it is possible to instantly andquantitatively recognize the displacement in an angle at which theoptical unit is attached.

With the present invention, it is possible to instantly andquantitatively recognize the displacement in an angle at which theoptical unit is attached and detect the coordinates of the position of ablockage corresponding to this displacement.

With the present invention, it is possible to visually recognize theoccurrence of displacement in an angle at which the optical unit isattached and detect the coordinates of the position of a blockagecorresponding to this displacement.

With the present invention, the configuration thereof can be simplifiedby suppressing an increase in the number of components.

With the present invention, any one of the coordinate-position inputdevices described above can be applied to a display board system.

Other objects and features of this invention will become understood fromthe following description with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an external view showing general configuration of thecoordinate-position input device according to the present invention;

FIG. 2A to FIG. 2C explain the elements constituting a reflecting memberlocated in the frame body and an arrangement thereof;

FIG. 3A and FIG. 3B explain a structure of an optical unit of thecoordinate-position input device;

FIG. 4A to FIG. 4C are external views of the frame edge with a magnet, ahook, and a form capable of being hung each employed as a mountingmember for the coordinate-position input device;

FIG. 5 is a block diagram showing a flow of coordinate-position inputdata among a computing section, a storing section, an input specifyingsection, and a control section as well as controls by the controlsection;

FIG. 6 explains a positional relation for computing a blocked point onthe touch-panel surface;

FIG. 7A and FIG. 7B show contents written on a white board and how thecontents are stored in a frame memory;

FIG. 8 is an external view showing appearance of the frame andreflecting members of the coordinate-position input device;

FIG. 9 is a general view showing a general configuration of thecoordinate-position input device which forms an outside shape with onlythe frame-ends sections obtained by accommodating the entire reflectingmembers and frame edges therein;

FIG. 10 is an external view showing appearance of an attachmentstructure between the detachable optical unit and the frame-endssection;

FIG. 11A and FIG. 11B explain examples of locations where the opticalunits can be attached;

FIG. 12A and FIG. 12B show external configuration of thecoordinate-position input device with reflecting members accommodated inthe optical unit and appearance when the device is used respectively;

FIG. 13 is a block diagram for explaining the coordinate-position inputdevice commonly used in Embodiments 3 and 4 of the present invention;

FIGS. 14A and 14B explain the structure of the optical unit in FIGS. 13,FIG. 14A is a side view of the optical unit, and FIG. 14B is a frontview thereof (a surface from which light is emitted);

FIGS. 15A and 15B show examples of structures where an indexing mark inthe side of an optical unit and an indexing mark in the side of a panelaccording to Embodiment 3 of the present invention are provided;

FIG. 16 explains a method of detecting the displacement of anoptical-unit attached angle according to Embodiment 3 of the presentinvention;

FIG. 17 is another view for explaining the method of detecting thedisplacement of an optical-unit attached angle according to Embodiment 3of the present invention;

FIG. 18 is a view for more specifically explaining the displacement ofan element for detecting a detection mark and displacement of anoptical-unit attached angle according to Embodiment 3 of the presentinvention;

FIG. 19 is a flow chart for explaining the processing in Embodiment 3 ofthe present invention;

FIG. 20 is a view for explaining tick marks provided for reading anoptical-unit attached angle according to Embodiment 4 of the presentinvention;

FIG. 21 is a block diagram for explaining the configuration of a displayboard system according to Embodiment 5 of the present invention;

FIG. 22 is a perspective view showing the display board system accordingto Embodiment 5 of the present invention and a housing unit with thedisplay board system accommodated therein;

FIG. 23 is a view for explaining a blockage detecting principle of thecoordinate-position input device such that light emitted from a lightsource is spread in a fan shape; and

FIG. 24 is a view sowing a relation between emission angle, a lightsource, and an attached angle of the light source shown in FIG. 23.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Detailed description is made hereinafter for Embodiments 1 to 5 of themethod and device for inputting coordinate position according to thepresent invention with reference to the attached drawings.

At first, a general configuration of the coordinate-position inputdevice will be described below. FIG. 1 is an external view showing ageneral configuration of the coordinate-position input device accordingto the present invention. The coordinate-position input device 100comprises a frame body having four edges 102A to 102D and having arectangular form. Reflecting members 103 for recursively reflectinglight are provided on the inner side of the four edges 102A to 102D. Twooptical units 101A and 101B (described the optical unit 101 hereinafterwhen the two optical units 101A and 101B are collectively described)each with a light source section are provided for irradiating lightwhich is substantially parallel with respect to a white board 110. Alight-receiving section which is integrated with the optical unit 101 isprovided for receiving light reflected from the reflecting members 103.A mounting member 104 is provided for detachably attaching the framebody to the white board 110. The two optical units 101A and 101B arelocated at the two ends of the edge 102A forming the frame body.Further, the optical unit 101 and the frame body are integrated to eachother.

The coordinate-position input device 100 has a processing unit 105comprising a computing section, a storing section, an input specifyingsection, and a control section each described later provided outside ofthe frame body and optical unit 101 which are integrated to each other.A pen 120 used for writing on the white board 110 is also shown in thefigure. It should be noted that a surface scanned with the lightirradiated from a light source to the white board 110 will be called atouch-panel surface.

Next, structure of the frame body, optical unit 101, mounting member104, and processing unit 105 in the order thereof will be described.

(Structure of the Frame Body)

The frame body in Embodiment 1 comprises rigid integrated frame edges102A to 102D having a rectangular shape, and reflecting members 103 arelocated in an inner side of the frame edges 102A to 102D. FIG. 2A andFIG. 2B show the elements constituting the reflecting members 103located in the frame body and FIG. 2C explains an arrangement thereof.The reflecting members 103 recursively reflect incident light from theoptical unit 101 thereto. In general, there has been known a corner cubereflector shown in FIG. 2A as a reflecting member having the recursiveproperty described here. The corner cube reflector is conical in shapehaving an apex angle of 90 degrees as shown in FIG. 2B. A material witha high reflectivity such as aluminum is provided on the inner surfacethereof. This shape is known to have recursive property based ongeometrical optics.

A corner cube array (Refer to FIG. 2C) where a large number of cornercube reflectors are arranged is embedded in the inner side of the framebody. As the frame body is integrally constructed and has rigidity,torsion is not generated among the four edges of the frame 102A to 102D.As high-reflectivity corner cube array is used for the reflecting member103, it is possible to provide a coordinate-position input device 100with optical unit 101 described later having an excellent inlight-receiving efficiency.

(Structure of the Optical Unit)

The optical unit 101 is located at both the ends of any of the frameedges 102A to 102D and each of which comprises a light source sectionand a light receiving section. FIG. 3A and FIG. 3B explain a structureof the optical unit 101. FIG. 3A is a side view of the optical unit 101and FIG. 3B is a front view thereof.

The light source section comprises a laser diode 201 for oscillating thelight, a diffusing lens 202 for diffusing the oscillated light to 90degrees, and a half mirror 205 for deviating the diffused light andirradiating it onto the reflecting members 103 of two frame edges (e.g.,frame edges 102B and 102C for the optical unit 101A). While the lightreceiving section comprises the half mirror 205 for passing therethroughthe reflected light recursively reflected by the reflecting members 103,a light-receiving lens 203 for converging the light passing through thehalf mirror 205, and a photosensor 204 for sensing the converged light.

The laser diode 201 is a laser diode which can emit infrared rays havinga wave length of 890 nm although one emitting a visible-light laser maybe used. There are advantages of using the infrared rays. For example,the infrared rays can be used even in a dark conference room or similarsituations and also that user's attention is not diverted to thevisible-light laser emitted from the light source. However, it isrequired to use appropriate wave length and light-emitting strength ofthe laser diode 201 to prevent the optical unit 101 from its getting toohot or from high probability of misidentification by catching otherinfrared rays in the light receiving section. It should be noted thatusing ultraviolet rays are not desirable because using ultraviolet raysfor a long time may be bad for the human body.

A combination of appropriate lenses is used as the diffusing lens 202 asnecessary. In the figure, a combination of flat concave lenses is used.Since two optical units 101 are used in principle in thecoordinate-position input device 100, the diffusing lens 202 is requiredto diffuse the light by at least 90 degrees. It should be noted that anydiffusing lens 202 may also be employed on condition that it diffuseslight over 90 degrees in parallel with the writing surface of the whiteboard 110 and at the same time only slightly diffuses the light in anormal direction with respect to the writing surface thereof. With thisfeature, even if the direction of light emitted from the light source isslightly displaced with respect to the frame body, the light isreflected by the reflecting members 103. This type of diffusion iseffective especially in a large frame body.

The light-receiving lens 203 plays a roll of converging the reflectedlight passing through the half mirror 205 towards the photosensor 204.Convergence of the light by the light-receiving lens 203 increases theintensity of the light so that a case where light is detected can easilybe discriminated from a case where light can not be detected (when lightis not detected due to a blockage on the touch-panel surface).

The photosensor 204 senses the reflected light converged by thelight-receiving lens 203 and detects a direction from which thereflected light can not be sensed. As a photosensor 204, there is a CCDline sensor as an example, and this sensor can detect the direction fromwhich the reflected light can not be sensed. It should be noted that anyphotosensor 204 enabling detection of a direction from which reflectedlight can not be sensed may be used. A mode may be used in which arotatable slit is provided in a section where reflected light isreceived on the optical unit 101 to recognize a direction from whichincident light can not be sensed or the like.

The photosensor 204 should effectively sense a wave length of light withhighest strength, so that the sensor may be selected by taking intoconsideration absorption and attenuation of light by an optical systembecause the light passes through various types of optical system. It isconsidered that light incident onto the photosensor 204 contain varioustypes of noise other than the light emitted by the laser diode 201.Therefore, it is required to use a laser diode 201 which can emit lightof such an intensity that the light finally passing through thelight-receiving lens 203 can be differentiated from the noise. By usingthe light having the intensity as described, it is possible to detectthe direction from which only light having an intensity as much as thatof noise can be sensed as a direction in which a blocked point ispresent on the touch-panel surface.

As a method of enhancing the sensing precision of the photosensor 204,there is also a method of, other than the method of makinglight-emitting power of the laser diode 201 higher, letting thereflected light of specified intensity into the photosensor 204 byproviding a filter immediately ahead of the photosensor 203 withoutbothering the reflecting direction.

A device emitting a fan-shaped light flux is used as the optical unit101. However, the optical unit 101 is not limited to the devicedescribed above, and there may be used an optical unit based on a typeof scanning a touch-panel surface with a light beam by using, forinstance, a rotating polygon mirror.

(Structure of the Mounting Member)

The mounting member 104 is made with any of a magnet, a hook, a formenabling hanging, a suction cup, a face-type fastener, an engaging form,and an adhesive or a combination thereof, and is provided with the framebody. FIG. 4A shows an external view of the frame edges when a magnet isemployed as the mounting member, FIG. 4B shows an external view of theframe edges when a hook is employed as the mounting member, and FIG. 4Cshows an external view of the frame edges when a form capable of beinghung is employed as the mounting member for the coordinate-positioninput device 100. The coordinate-position input device 100 can easily beattached to the white board 110 and another component of display unit byone of these mounting members 104 with a simple structure or can fix aposition of the white board with respect to other display unit.

The frame body can be mounted on the white board 110 in either thelongitudinal direction or in the lateral direction thereof by one ofthese mounting members 104, so that mounting flexibility can beenhanced. The mounting member 104 (a hook) in FIG. 4B has a shaft in thecenter thereof and is rotatable around the shaft, so that the frame bodycan be mounted on the white board in either the longitudinal directionor the lateral direction thereof. Also the mounting members 104 (a formcapable of being hung) in FIG. 4C are provided at both ends of each ofthe frame edges 102A to 102D, so that the frame body can also be mountedon the white board in either the longitudinal direction or the lateraldirection thereof.

It should be noted that a positional relation between the frame body andthe white board 110 may not necessarily be such that both of them comein contact with each other. That is because, there may be a caserequired for preventing the miss-entry of a coordinate position whichmiss-entry is caused due to deposit or adhering of powder of a chalk ordust generated when a writing with a pen is erased onto the reflectingmember 103 when the frame body and the white board come in contact witheach other. Also if the form capable of being hung is employed as amounting member 104 and the frame body is hung from a ceiling, thecoordinate-position input device 100 can be fixed to the existing whiteboard 110 to which the coordinate-position input device 100 can notdirectly be attached.

Next, the processing unit 105 comprising a computing section, a storingsection, an input specifying section and a control section will bedescribed. FIG. 5 is a block diagram showing a flow ofcoordinate-position input data among the computing section 106, storingsection 107, input specifying section 108, and control section 109 inthe processing unit 105 as well as controls by the control section. Inthe processing unit 105, the computing section 106 computes a coordinateposition of a blocked point where light is blocked by the pen 120 usedfor writing on the white board 110 through the touch-panel surface froma direction from which reflected light can not be received by alight-receiving section as well as from a distance between the two lightreceiving sections. The storing section 107 stores therein the computedcoordinate position. With the input specifying section 108, whether acoordinate position is to be inputted or not can be selected. Thecontrol section 109 provides controls over the optical unit 101 andcomputing section 106 according to specification by the input specifyingsection 108.

(Configuration of the Computing Section)

The computing section 106 computes a coordinate position of the blockedpoint from a distance between the light receiving sections and thedirection from which light can not be sensed by the light receivingsection due to a blocked point on the touch-panel surface blocked by thepen 120. If required, the computing section 106 also converts thecomputed coordinate position to an integer value as a grid value of thedisplay surface. At first, a principle of computing a position of ablocked point will be described.

FIG. 6 is an explanatory view for explaining a positional relation forcomputing a blocked point on the touch-panel surface. It should be notedthat the explanation is the same as that described with respect to aboveEquation (1) for obtaining a point on the optical axis.

Namely, when coordinate values are set as shown in the figure, a blockedpoint, namely a position (x, y) written with a pen 120 on the whiteboard 110 is uniquely expressed as follows assuming that a distancebetween the light receiving section of the optical unit 101A and thelight receiving section of the optical unit 101B is W and angles eachbetween each of the light receiving sections and a reference line (aline linking the two light receiving sections) are θ_(L) and θ_(R):

x _(p)=(W·tan θ_(R))/(tan θ_(L)+tan θ_(R))

y _(p) =x _(p)·tan θ_(L)

The coordinate of the blocked point (x, y) computed using the aboveequation is generally a number with a decimal point. If this computationis executed in single precision or double precision in the computingsection 106, a high-precision coordinate position can be obtained.However, processing of computation with a decimal point takes long time,which increase the load onto the computing section 106. On the otherhand, coordinate position data to be stored in the storing section 107described later does not also require an accurate value with a decimalpoint on condition that the data is provided for the purpose thatcontents written on the white board 110 can be stored so as to becapable of easily interpreting them.

When an accurate coordinate position is not required as described above,it is simple and convenient that virtual x axis and y axis and a virtualgrid, for instance, a grid with resolution of XGA (1024×768) areprovided on the touch-panel surface of the coordinate-position inputdevice 100. Further, a blocked point (x, y) is once computed, and thenthe computed values are replaced with a corresponding integer value onthe grid, and that the processing thereafter (e.g., processing ofstoring the value in the storing section 107) is executed.

(Configuration of the Storing Section)

The storing section 107 stores therein a coordinate position computed bythe computing section 106. When a coordinate position is replaced with agrid value, as each point is indicated by 1 bit assuming that a blockedposition (in reverse video) is 1 and a not blocked position (in normalvideo or not displayed) is 0, there are 1024×768=786432 bits displayedbased on the XGA, and so the storing section 107 can store thereininformation for a full screen as frame memory with less than 100 Kbytes.FIG. 7A shows contents written on the white board 110 and FIG. 7B showshow the contents are stored in the frame memory.

The storing section 107 can store therein a locus of a blocked point notas frame memory but as time-varying histories. In such a case, arecording time is decided by updating intervals of the frame and storagecapacity, and so image information for 90 minutes can be stored in a 540M-storage medium even if, for instance, one frame is stored at onesecond intervals.

As a manner of storage, data may be stored in an entirely non-compressedform like BMP file or may be stored in a compressed form like a JPEG orGIF format. In order to leave histories with time, a general-purposestorage form such as a form of AVI file is employed.

A storage medium employed as the storing section 107 includes ageneral-purpose storage medium such as a floppy disk, a card memory (anATA flash-memory card, a compact flash card, PCMCIA hard disk card orthe like), a CD-RW, and a DVD. A processing unit 105 which can use aPCMCIA type II of card is utilized in the coordinate-position inputdevice 100 shown in FIG. 1. When the storing section 107 is provided inthe coordinate-position input device 100, contents of the white board110 can be recorded without using any special external equipment. Usingthe general-purpose storage medium means employment of thegeneral-purpose equipment for an interface device, and with thisfeature, the storage medium is detached from the processing unit 105,which allows the image information to be printed by using anotherexternal equipment such as a personal computer and historical data ondrawing can be reproduced like a movie.

(Configuration of the Input Specifying Section and the Control Section)

The input specifying section 108 exclusively specifies any of thecoordinate-position input mode for inputting a coordinate positionthrough the touch-panel surface and the input suspend mode for notinputting a coordinate position. This is required to prevent suchinconvenience that when drawn contents on the white board 110 are erasedwith an eraser for a blackboard and if the light receiving sectiondetects the eraser as a blocked point as it is, the drawing drawn so faris filled in with black. By using the exclusive specification whenrecording in the frame memory is started anew, contents described on thewhite board 110 can be stored for each drawn-contents break.

The control section 109 provides controls over at least one of theoptical unit 101 and computing section 106 to control processing whethera coordinate position is to be inputted or not. Other than this control,the control section 109 provides controls for input or output of ageneral-purpose storage medium.

In the coordinate-position input device 100 in Embodiment 1, the framebody with the integrated optical unit 101 can easily and detachably beattached to existing white board 110 or a display unit by means of themounting member 104 provided on the frame body. It is possible to storecharacters and graphics drawn on the writing surface of the white board110 or the display surface of the display unit in a general-purposestorage medium so as to be readable, and easily print (record) thecontents without copying the contents by hand which is troublesome tothe user.

In the coordinate-position input device in Embodiment 2, frame edgeswhich form the frame body are extendable in multi-steps in addition tothe feature that the device can detachably be attached to a white boardor a display unit with the help of a mounting member. It should be notedin Embodiment 2 only those points which are different as compared toEmbodiment 1 will be described unless otherwise specified. Further, samenames and reference numbers are used for the sections which have same orsimilar functions as those in Embodiment 1.

FIG. 8 is an external view showing appearance of the frame andreflecting members of the coordinate-position input device according toEmbodiment 2. Frame edges 302A to 302D which form the frame body of thecoordinate-position input device 300 have a nesting structure. The frameedges 302A to 302D as well as reflecting members 303A to 303D areaccommodated in frame-ends sections 301A to 301D respectively. Since theframe edges 302A to 302D are extendable in a multi-step, the size of thecoordinate-position input device 300 can be changed according to thesize of the white board or the display unit to be used. The mountingmembers 104 are provided on each of the frame-ends sections 301A to301D. With these mounting members 104 the device can be attached to thewhite board or the display unit. It should be noted that, the term‘frame-ends section 301’ will be used hereinafter to indicatecollectively the frame-ends sections 301A to 301D, and the term‘reflecting member 303’ will be used hereinafter to indicatecollectively the reflecting members 303A to 303D.

The reflecting member 303 used in the coordinate-position input device300 is made with a reflective tape having the property of recursivelyreflecting the incident light similarly to that of the above describedcorner cube array. The reflecting member 303 can be wound into a rolland accommodated in the frame-ends sections 301A to 301D. FIG. 9 shows ageneral configuration of the coordinate-position input device 300 whichhas an outer shape of the frame-ends section 301 when the all thereflecting members 303A to 303D as well as the frame edges 302A to 302Dare accommodated therein. The optical unit 101 or the like is omitted inthis figure because the figure is intended only to show how thereflecting members 303A to 303D and the frame edges 302A to 302D areaccommodated in the frame-ends section 301.

A spring or the like is provided in the center of each roll although itis not shown in the figure, and the reflecting members 303A to 303D arestretched each with the tension maintained constant regardless of thesize of a frame body. The coordinate-position input device 300 can beused in accordance with the size of a white board or a display unit tobe used because its frame edges 302A to 302D are extendable inmulti-steps, and in addition, its accommodation, transportation, andinstallation or the like can easily be realized.

In FIG. 8 and FIG. 9, the reflecting members 303A to 303D and the frameedges 302A to 302D are separated from each other. However, a reflectivetape may be adhered on the inner side of the frame edges 302A to 302D ora corner cube array may be integrated thereto in the same manner as thatin Embodiment 1. When the recursive reflectivity of the reflective tapeis low, then an optical unit for irradiating a light beam by using arotating polygon mirror may be used.

The optical unit 101 of the coordinate-position input device 300 candetachably be attached to the frame-ends section 301 with an irradiatingdirection of light from the optical unit 101 adjustable. FIG. 10 showsan attachment structure for attaching the detachable optical unit 101Ato the frame-ends section 301A. In this figure, the optical unit 101Aand the frame-ends section 301A are attached to each other with a screw.A universal joint (hook joint) is provided on the upper side of thescrew of the optical unit 101A so that light can be irradiated in anydirection. It should be noted that a detachable structure of the opticalunit is not limited to the screw, and any structure may be employed oncondition that the optical unit is detachably fixed to the frame-endssection. A structure for adjusting the irradiating direction of lightfrom the optical unit is not limited to the universal joint, and anystructure may be employed on condition that the optical unit can bedirected in any direction and fixed. Also in this figure, the opticalunit 101A is attached on the outside of the frame-ends section 301A, buta structure in which the optical unit is attached inside the frame-endssection 301A may be allowable.

Screw holes are provided at all of the frame-ends sections 301A to 301D,and so optical units can be attached to any adjacent frame-ends sections301. FIG. 11A and FIG. 11B show examples of locations where the opticalunits 101A and 101B may be attached. For example, as for the locationsfor their attachment shown in FIG. 11A, a frame edge not particularlyrequiring reflection is a bottom edge, so that there is comparatively alesser chance of occurrence of reflection failure due to chalk powder orthe like. In the locations for their attachment shown in FIG. 11B, thereis less probability of occurrence of a case that the light receivingsection may misidentify light when sun-light or the like enters adisplay surface from the left side thereof.

By designing the optical unit 101 in such a way that it can bedetachably attached to the frame-ends section 301, the optical unit 101can be fixed to any of the four frame-ends sections 301 and fixed in anyof directions. Therefore, flexibility required when thecoordinate-position input device 300 is fixed to the white board 110 isenhanced, which makes it possible to adjust the irradiating direction oflight so as to obtain the most appropriate reflective intensity.

The coordinate-position input device 300 may also have a structure inwhich the reflecting member 303 is directly accommodated in the opticalunit 101. FIG. 12A and FIG. 2B show external configuration of thecoordinate-position input device 300 with the reflecting member 303accommodated in the optical unit 101 and appearance when the device isused. FIG. 12A is an external view of the coordinate-position inputdevice 300 when the entire reflecting member 303 is accommodatedtherein, and FIG. 12B is a view showing how the coordinate-positioninput device 300 is attached to the white board 110 to be used. In thiscase,a tape or a wire reflecting member 303 is used. However, it isrequired to support, by providing corners as necessary when the memberis used, the member so as to surround the full surface of the whiteboard 110. A magnet is used herein as the mounting member 104.

In the coordinate-position input device 300 in Embodiment 2, as themounting members 104 are provided, the optical unit 101 and frame bodycan be easily and detachably attached to an existing white board 110 ora display unit. As the optical unit 101 is detachably attached to theframe body with an irradiating direction of light therefrom adjustable,the user can select any location which has a high precision of detectinga coordinate position. Further, as the frame edges 302A to 302D whichform the frame body of the coordinate-position input device 300 areextendable, the coordinate-position input device can be used inaccordance with the size of a white board or a display unit to be used,so that general versatility is enhanced.

FIG. 13 is a block diagram of the coordinate-position input deviceaccording to Embodiments 3 to 5 of the present invention. Thecoordinate-position input device 400 shown in this figure is largelydivided into an input section 50 with a character or an image byhandwriting inputted therein, and a control section 55 for providingcontrols for processing or the like related to detection of a characteror so inputted into the input section 50.

The input section 50 has a panel 80 such as a panel for defining aninput area, an optical unit 20 and an optical unit 30 each for emittinglight to the panel 80. A frame body 1 is provided on three sides of thepanel 80, and a reflecting member 2 such as a reflective tape forreflecting light emitted from the optical units 20 and 30 is attached onthe inner side of the frame body 1 (surface towards the panel) so as toreflect the light emitted from the optical units 20 and 30 along thesame optical axis as that on its emission.

It should be noted that each of the optical unit 20 and optical unit 30is formed by integrating a light source 21 (Refer to FIG. 14A and FIG.14B) for emitting light flux over a substantially entire area of thepanel 80 and a CCD line sensor 29 (Refer to FIG. 14A and FIG. 14B) as alight detecting unit for detecting the reflected light of the lightemitted from the light source. The structure of this type of opticalunit 20 and optical unit 30 will be explained later.

On the other hand, the control section 55 has a control unit 10, apersonal computer 5 (abbreviated as PC hereinafter) connected to thecontrol unit 10 and functioning as an operating section for inputting aninstruction to the control unit 10, and an interface section 3 foroutputting a signal from the control unit 10 to the PC 5. Further, thecontrol unit 10 has a CPU 12 and a storing section 14.

A signal outputted from the CCD line sensor 29 provided in each of theoptical unit 20 and optical unit 30 and is input into the CPU 12 where aposition of a blockage such as due to a pen tip is calculated throughcomputation based on this signal. The storing section 14 comprises a ROM14A for storing therein data required for computing in the CPU 12 and aRAM 12B for successively storing positions of the blockage obtained bythe CPU 12.

FIG. 14A and FIG. 14B are views for explaining the structure of theoptical units 20 and 30, and FIG. 14A is a side view of each of theoptical units 20 and 30 and FIG. 14B is a front view thereof (a surfacefrom which light is emitted). It should be noted that the optical unit20 and optical unit 30 are a pair of units each having the samestructure. Therefore, only the optical unit 20 attached to the left sideof the panel 80 in FIG. 13 will be described with reference to FIG. 14Aand FIG. 14B. Namely, the optical unit 30 is not shown in these figuresand description thereof is also omitted herein.

The optical unit 20 comprises a light source 21 for outputting a lightbeam, a lens section 23 for diffusing the light emitted from the lightsource 21, a lens section 27 for converging the reflected light of thelight converged in the lens section 23, a CCD line sensor 29 for sensingthe light converged in the lens section 17, and a half mirror 25 forreflecting the emitted light to the panel 80 and also passingtherethrough reflected light to the lens section 27. All the membersdescribed above are fixed in a case body 22 and are integrated into oneunit.

The light beam outputted from the light source 21 is diffused in thelens section 23 in a direction perpendicular to the optical axis of thebeam, then the light beam is reflected by the half mirror 25 towards thepanel 80 and finally emitted to the outside of the case body 22. As aresult, a fan shaped light flux spreads at an emission port (not shownherein) as a pivot provided in the case body 22. Then, the lightirradiated onto the panel 80 is reflected by the reflecting member 2provided on the sides of the panel 80. When reflecting the light, thereflecting member 2 reflects all the light beams forming the fan-shapedlight flux so that the beams are reflected along the same direction asthe optical axis on their emission. Therefore, all the light beamsreturn to the case body 22 and are converged by passing through the halfmirror 25, and finally they are detected by the CCD line sensor 29.

In the optical unit 20 having the structure described above, if there isa obstacle on the panel 80 then the light is blocked by this obstacleand the light is not detected by the CCD line sensor 29. Therefore, ifan element of the CCD line sensor 29 which does not receive the lightcan be detected, then the emission angle θ_(L) of the blocked light canbe obtained from the position of this element. The emission angle θ_(L)Of the blocked light straightforwardly represents an angle of the axiswhere the obstacle exists. Consequently, if the other axis passingthrough a point where the obstacle exists is obtained from a result ofdetection by the other optical unit 30 then the coordinates of a pointwhere the obstacle exists can be obtained through computation as anintersection of the two axes.

Each of the optical unit 20 and optical unit 30 according to Embodiment3 has the members (light source 21, lens section 23, half mirror 25,lens section 27, and CCD line sensor 29) for obtaining data used fordetecting a coordinate position of an obstacle as described above allintegrated into one unit. Therefore, a positional relation between themembers such as the light source 21, lens section 23, half mirror 25,lens section 27, and CCD line sensor 29 can be maintained in a constantstatus at any time.

Therefore, if attachment or detachment of the light source 21 and CCDline sensor 29 to or from the panel 80 is carried out for each of theoptical unit 20 and optical unit 30 as a whole, the need for alignmentto make sure that central axes of the members are in the right place andeach distance therebetween is correctly spaced is eliminated. It is alsopossible to prevent precision of detection before and after itsattachment and detachment from its variation and to enhance reliabilityof a result of detection.

Further, in Embodiment 3, only once when each of the optical unit 20 andoptical unit 30 is constructed, the members located on the inner sidethereof may be aligned with each other with high precision. Therefore,the number of times of aligning the members used for detection of ablockage may be a minimum number, so that Embodiment 3 is easier to beapplicable even to a method of alignment thereof which takes acomparatively longer time.

Next, alignment of the optical unit and the panel described above willbe described. FIG. 15A and FIG. 15B are views showing examples ofstructures where an indexing mark is provided in the optical unit and anindexing mark is provided to the panel at a position where the opticalunit is to be attached. In Embodiment 3, as it is required to irradiatefan-shaped light onto the panel, optical units are attached to cornersof the panel where each angle of irradiating light is small so that thelight can spread over the entire area of the panel.

FIG. 15A is a cross section of an optical unit 221 with a concavesection 221 a as an indexing mark provided therein, and a cross sectiona panel 81 with a convex section 81 a as an indexing mark providedtherein for engaging with the concave section 221 a of the optical unit221. The concave section 221 a and the convex section 81 a are formed soas to be coupled, and when the optical unit 221 is attached thereto, theconvex section 81 a is inserted into the concave section 221 a. FIG. 15Bshows a cross section of an optical unit 222 with a convex section 222 aand a convex section 222 b each as an indexing mark in the side of theoptical unit provided thereon, and a top face of a panel 82 with aconcave section 82 a as a long hole and a concave section 82 b as anordinary hole each as an indexing mark in the panel side providedtherein. The convex section 222 a is formed so as to be coupled to theconcave section 82 a and the convex section 222 b is formed so as to becoupled to the concave section 82 b respectively. The indexing mark inthe optical unit side and the indexing mark in the panel side shown inFIG. 15A and FIG. 15B are engaged in the corresponding marks when theoptical unit is attached thereto, so that the optical unit can beattached to the panel in the right place.

In Embodiment 3 described above, precision of alignment between memberscan be enhanced by integrating a light source and a CCD line sensor intoone unit, and precision of alignment of an optical unit to a panel canalso be enhanced by providing indexing marks therein respectively. Thestructure in Embodiment 3 described above can prevent precision ofdetecting a blockage or reproduction of information from its variationdue to attachment or detachment of the optical unit to or from thepanel.

By the way, in recent years, a coordinate-position input device with anoptical unit removable from a panel has been studied for the purpose ofmaking the coordinate-position input device more transportable. Thecoordinate-position input device according to Embodiment 3 having thestructure described above is preferably applied especially to thisdemanded coordinate-position input device.

The method of attaching the optical unit to the panel and adjusting theattached angle thereof will be described hereinafter.

FIG. 16 and FIG. 17 are views each for explaining a method of detectinga displacement in the angle at which the optical unit is attached(optical-unit attached angle). FIG. 16 is a view showing a panel 83having a detection mark 40 for detecting an optical-unit attached angleand an optical unit 20 attached to the panel 83 at its attached angleβ′. The section of the panel 83 to which the optical unit 20 is attachedis slightly thicker as compared to the section in the inner sidethereof, which allows strength of the panel to be insured. In theoptical unit 20 shown in the figure, a part of the figure to representthe incorporated members is omitted to make description simpler and onlythe CCD line sensor 29 and light source 21 are shown herein.

In the CCD line sensor 29, when the optical unit 20 is attached at anappropriate attached angle β_(L), an element located in a specifiedlocation A detects the detection mark 40 as shown in FIG. 17, namely,the element is previously set so as not to detect light. When anattached angle of the optical unit 20 is displayed from the appropriateattached angle β_(L), the detection mark 40 is detected by an element,for instance, at a location B displaced by a distance a from the elementat the location A of the CCD line sensor 29.

FIG. 18 is a view for more specifically explaining displacement of anelement for detecting the detection mark 40 and displacement of anattached angle of the optical unit 20. When the optical unit 20 isattached to the panel at the appropriate attached angle β_(L), it isassumed that the CCD line sensor 29 is located at the location p1 anddetects the detection mark 40 with the help of the element at thelocation A. The CCD line sensor 29 described above moves, when theattached angle of the optical unit 20 is displaced from β_(L) to β′, tothe location p2 in association with this displacement. Thus, the elementwhich detected the detection mark 40 is shifted from the location A tothe location B.

According to FIG. 18, the attached angle of the optical unit 20corresponds to a location (detecting location) for detecting thedetection mark 40 on the CCD line sensor 29 one-to-one, and the degreeof displacement of attached angles (the angle β_(L) as a reference) isproportional to the degree of displacement of detecting locations (thedetecting location A corresponding to the angle βL as a reference).Accordingly, the relation as follows holds:

β′/β_(L)=(A+a)/A  (6)

However, the value of a is positive when an element detecting thedetection mark 40 moves away from the location of O in the figure whilethe value of a is negative when the element moves closer to the locationof O.

In Embodiment 3, for instance, the angle β_(L), position A, and theequation (6) are previously stored in the ROM 14A of the control unit55. Then, a result of detection in the CCD line sensor 29 is inputtedinto the CPU 12 and an actual attached angle β′ is computed based on alocation of the element detecting the detection mark 40 as (A+a).Equation (5) is corrected by using the computed value β′ as an angleβ_(L) in Eq. (5). At this time, the location A of the element and thedisplacement rate a may be a number of elements based on the element atthe location of O as a reference, or may be a value obtained byconverting this number of elements to a distance.

In accordance with Embodiment 3, the displacement of the angle at whichthe optical unit is attached to the panel can be corrected throughcomputation. Accordingly, emission angle can be computed accuratelywithout requiring mechanical enhancement of attaching precision of theoptical unit.

A series of processing performed in the coordinate-position input deviceaccording to Embodiment 3 will be described below with reference to aflow chart.

FIG. 19 is a flow chart for explaining the processing in thecoordinate-position input device according to Embodiment 3. Theprocessing shown in FIG. 19 is executed as follows. For instance, afteran instruction to start the processing is inputted from PC 5, a resultof detection in the CCD line sensor 29 is inputted from an optical unitR located, for instance, at the right corner of the panel 80, andwhether there is any displacement in an attached angle of the opticalunit R or not is determined (step S1). As a result of this, when it isdetermined that there is some displacement in the attached angle thereof(step S1: Yes), actual attached angle thereof is computed through theequation (6). Then, the equation (5) stored in the ROM 14A is read outonto the CPU 12, and the actual attached angle is substituted thereintoto correct the equation for computing emission angle θ_(R) (step S2). Atthis point, the corrected equation may be stored in the RAM 14B asrequired.

Then, a result of detection in the CCD line sensor 29 is inputted froman optical unit L located at the left corner of the panel, and whetherthere is a displacement in an attached angle of the optical unit L ornot is determined in the same manner as that in step S1 (step S3). As aresult of this, when it is determined that there is a displacement inthe attached angle thereof (step S3: Yes), equation (5) is read out ontothe CPU 12, and the computed actual attached angle is substitutedthereinto to correct the equation for computing the emission angle θ_(L)(step S4). When it is determined in step S1 and step S3 that there is nodisplacement in the optical-unit attached angle, both the equations forcomputing the emission angles θ_(R) and θ_(L) stored in the ROM 14A areread out onto the CPU 12, and are applied without correction thereto toobtain the emission angles respectively.

Then, it is determined whether a blockage is detected or not (step S5),and when it is determined that the blockage is detected (step S5: Yes),a coordinate position (x_(p), y_(p)) of the blockage is computed byusing the equation in the CPU 12 (step S6), and this coordinate positionis stored in, for instance, the RAM 14B (step S7). Then, it isdetermined whether or not an instruction to end the entry into thecoordinate-position input device is given from the PC 5 or the like(step S8). When it is determined that such an instruction is not input(step S8: No), the processing is returned to the step where detection ofa blockage is determined again (step S5). On the other hand, when it isdetermined that the instruction to end the entry is given thereto (stepS8: Yes), the processing of the flow chart is ended.

It should be noted that the present invention is not limited toEmbodiment 3 described above. In Embodiment 3, for instance, althoughthe optical unit is directly attached to the panel, the unit may beattached thereto through a frame body. Also in Embodiment 3, although aCCD line sensor is used as a light detecting unit, the present inventionis not limited to the configuration as described above, and any sensormay be employed on condition that the emission angle of the light whichshould have passed if the obstacle were not there can be determined fromreceived reflected light.

Next, Embodiment 4 of the present invention will be described.

In Embodiment 4, tick marks are provided in the panel side so that theoptical-unit attached angle can visually be read thereby and a user caninput the read optical-unit attached angle through, for instance, the PC5. Even in such a Embodiment 4, the CPU 12 corrects the equation usedfor computation when coordinates of a position of a blockage accordingto a difference between an inputted optical-unit attached angle and anattached angle at which the optical unit should be attached thereto.

FIG. 20 is a view showing a panel 84 having a tick mark section 42provided thereon for visually reading the optical-unit attached angle aswell as shows the optical unit 20 attached to the panel 84 at anattached angle β′. It should be noted that, the optical unit 20 in FIG.20 shows, in the same manner as the optical unit shown in FIG. 16, onlythe CCD line sensor 29 and the light source 21.

The tick mark section 42 has a scale y_(L) with tick marks divided inthe vertical direction and a scale x_(L) with tick marks divided in thehorizontal direction in the figure. With this tick mark section 42, theuser can get to know displacement in the attached angle of the opticalunit 20 with respect to the panel 84 from the tick marks on the scaley_(L) and the scale x_(L) each crossing the case body 22 of the opticalunit 20.

Namely, in Embodiment 4, the reading of tick marks on the scale y_(L)and scale x_(L) when the optical unit 20 is attached to the panel 84 atan appropriate attached angle β_(L) is previously stored, for instance,in the ROM 14A. Then, the user reads the actual tick marks on the scaley_(L) and the scale x_(L) and inputs the read values. The CPU 12compares the tick marks on the scale y_(L) and the scale x_(L) stored inthe ROM 14A to the inputted read values, and when the values aredifferent therefrom, it is determined that a displacement has occurredin the attached angle of the optical unit 20. Then, the CPU 12 computesan actual attached angle β′ according to the stored tick marks and theread values, and employs the actual value in place of the value β_(L) inequation (5) to compute the emission angle.

In Embodiment 4, with the configured as described above, it is possibleto determine the displacement in the angle at which the optical unit 20is attached to the panel 84 with simpler configuration as compared tothat of detecting the detection mark 40 by the CCD line sensor 29. Thus,the invention according to Embodiment 4 can more easily correct thedisplacement in the attached angle of the optical unit 20 in addition tothe effects obtained in Embodiment 3.

Next, Embodiment 5 of the present invention will be described.

In Embodiment 5, any of the coordinate-position input device accordingto the above described Embodiment 3 and Embodiment 4 can be employed asa coordinate-position input device for a display board system.

FIG. 21 is a block diagram for explaining the configuration of a displayboard system according to Embodiment 5 of the present invention. Theconfiguration shown in FIG. 21 is substantially the same as that shownin FIG. 13, so that the same reference numerals are assigned to the sameconfiguration, and description thereof is omitted herein. Theconfiguration shown in FIG. 21 is largely divided into an input section51 from where a character or an image by handwriting can be inputted,and a control section 55 for providing controls for processing ofdetecting a character or so inputted into the input section 50 as wellas of recording it. It should be noted that the input section 51 has awhite board 7 provided in the back side of the panel 80 shown in FIG.13. The control unit 55 is further connected to a printer 9 and canprint the contents displayed on the white board 7 onto a paper.

FIG. 22 is a perspective view showing the display board system 500according to Embodiment 5 and a housing unit 600 with the display boardsystem 500 accommodated therein. The housing unit 600 comprises a panelsection 500 with the input section 51 incorporated therein, a controlleraccommodating section 60 with the control unit 10 accommodated therein,an equipment accommodating section 61 with the PC 5 and the printer 9accommodated therein, and further a caster section 70 for loadingthereon the housing unit 600 as a whole to making the unittransportable.

The frame body 1 having the reflecting member 2 as well as optical units20 and 30 are integrated to each other so as to be positioned in frontof the white board 7 and accommodated in the panel section 500. When theuser writes a character or the like on the white board with a pen,coordinate positions of this pen tip are successively read inassociation with movement of the pen tip. The read-in coordinatepositions are accumulated in the RAM 14B by the control unit 10, andrecorded therein as the locus of the pen tip, namely as a form of thewritten character and further the written contents.

The contents recorded as described above are sent to the printer 9through the PC 5 to be printed onto a paper. Audiences hearing thepresentation by using this display board system need not copy thewritten contents into a notebook or the like, which allows the audiencesto concentrate on what is being presented. The contents send to the PC 5can also be stored on an external memory such as a floppy desk herein.Therefore, the contents can arbitrarily be edited afterward.

In Embodiment 5 described above, the display board system is constructedwith the coordinate-position input device described in Embodiment 3 orEmbodiment 4, so that it is possible to detect the locus of a pen tipwith high precision and accurately read the contents thereon. Thus, itis possible to provide a display board system enabling accuratereproduction of contents after the presentation.

In Embodiment 5 described above, the display board system is constructedwith the coordinate-position input device described in Embodiment 3 orEmbodiment 4, so that it is possible to instantly and quantitativelydetect locational displacement in optical unit 20 and optical unit 30and further correct the equations used for computing a position of a pentip according to this displacement rate. Therefore, even if locationaldisplacement occurs in the optical unit 20 and optical unit 30 due tochange over time such as loose screws or shock, this displacement doesnot cause misidentification of a position of a pen tip. AccordinglyEmbodiment 5 can provide a high-reliability display board system.

It should be noted that the present invention is not limited toEmbodiment 5 described above. For instance, as a display section, ablackboard or a plasma display or the like may be used other than thewhite board.

As described above, the present invention can input a coordinateposition, by detachably attaching a frame body with two optical unitsintegrated to each other to a writing surface of a white-board or adisplay surface of a display unit, forming a touch-panel surface byusing the two optical units as well as reflecting members located in theframe body and detecting a position where the light for forming thetouch-panel surface is blocked, on the writing surface or the displaysurface thereof, so that general versatility applicable to an ordinarydiscrete white board is provided.

The present invention can input a coordinate position, by detachablyattaching a frame body to a writing surface of a white board or adisplay surface of a display unit using mounting members, furtherattaching two optical units to the frame body to adjust each irradiatingdirection of light therefrom, forming a touch-panel surface with the twooptical units as well as reflecting members located in the frame bodyand detecting a position where the light for forming the touch-panelsurface is blocked, on the writing surface or the display surfacethereof, so that the user can select arrangement with which the highestprecision of detecting a coordinate position can be obtained.

In the present invention, a computing section computes a coordinateposition of a blocked point on the writing surface or the displaysurface from a direction of reflected light not received by lightreceiving sections of the two optical units as well as from a distancebetween the light receiving sections thereof, so that a coordinateposition of the blocked point can be outputted from thecoordinate-position input device.

In the present invention, when a coordinate-position input mode and aninput suspend mode are exclusively specified by a specifying unit, acontrol unit provides controls over the two optical units and/or thecomputing section according to the specified mode, which allows the userto freely select either the case where a coordinate position is inputtedthrough the touch-panel surface or the case where a coordinate positionis not inputted, so that convenience when drawn contents on a whiteboard are modified is enhanced.

In the present invention, the frame body can be attached in any of thelongitudinal direction and the lateral direction, which allowsflexibility for attaching the frame body to a writing surface of a whiteboard or a display surface of a display unit to be enhanced, so that itis possible to provide a high-convenience coordinate-position inputdevice.

In the present invention, the mounting member is made with any of amagnet, a hook, a form enabling hanging, a suction cup, a face-typefastener, an engaging form, and an adhesive or a combination thereof,which allows the device of the invention to be attached to the whiteboard or display unit with its simple structure, so that it is possibleto provide a high-convenience coordinate-position input device.

In the present invention, each edge of the frame is extendable inmulti-steps by an adjustment mechanism, and the reflecting member iswound into a roll inside the adjustment mechanism when the frame edge iscontracted, so that the device of the invention can be used with theframe body contracted when it is to be carried and extended when it isto be used, which allows its transportability to be enhanced.

In the present invention, each edge of the frame is extendable inmulti-steps by an adjustment mechanism, and the reflecting member isextendable is also extendable in multi-steps together with the frameedge, so that the device of the invention can be used with the framebody contracted when it is to be carried and extended when it is to beused, which allows its transportability to be enhanced.

In the present invention, the coordinate position of the obstacle can bestored in a storing section, so that contents on the writing surface ofa white board or contents on the display surface of a display unit canbe stored in the coordinate-position input device.

In the present invention, the coordinate position of the obstacle can bestored in an external memory, and the stored contents are easily beaccessed by utilizing some other equipment by attaching the externalmemory thereto, so that it is possible to provide a high-conveniencecoordinate-position input device.

In the present invention, the coordinate position of the obstacle can bestored on a frame memory, so that efficiency when drawn contents on awhite board is processed is enhanced.

In the present invention, even before or after when a light emittingunit and a light detecting unit are attached or detached thereto ortherefrom, a positional relation between the light emitting unit and thelight detecting unit can be maintained to be constant at any time.Therefore, reliability of detecting a posit ion of a blockage is notaffected by such an attachment or detachment. Each of the light emittingunit and light detecting unit can be aligned for each unit, so thatalignment between the light emitting unit and light detecting unit canbe made comparatively easily and with high precision.

In the present invention, even before or after when a light emittingunit and a light detecting unit are attached or detached to or from anarea defining member, a positional relation between the light emittingunit and the light detecting unit can be maintained to be constant atany time, and in addition the state of emission and detection can alsobe maintained to be constant at any time. Therefore, an effect toprevent reliability of detecting a position of a blockage from itsreduction due to their attachment and detachment is further enhanced.Also, the state of detection including the light emitting unit and lightdetecting unit can be aligned as one unit, so that alignment between thelight emitting unit and light detecting unit can be made comparativelyeasily and with high precision.

In the present invention, the precision of alignment between the opticalunit and an area defining member is comparatively easily be enhanced byproviding indexing marks in side of the-optical unit as well as in theside of the area defining member. Therefore precision of detecting ablockage is comparatively easily enhanced, so that it is possible toprovide a coordinate-position input device enabling accurate entry of acoordinate position of an inputted character or the like.

The present invention further comprises an attached-angle measuringunit, and instantly recognizes displacement in an optical-unit attachedangle. Therefore, it is possible to provide a coordinate-position inputdevice enabling accurate entry of a coordinate position of an inputtedcharacter or the like by instantly reflecting the displacement to theprocessing thereafter and detecting an accurate position of a blockage.

The present invention instantly recognizes displacement in anoptical-unit attached angle and detects coordinates of the position of ablockage by correcting an operation equation in response to thisdisplacement. Therefore, it is possible to provide a coordinate-positioninput device enabling accurate reading of written contents by correctingthis displacement more easily and accurately detecting coordinate valuesof the position of the blockage.

In the present invention, occurrence of displacement in an optical-unitattached angle is visually recognized and coordinates of the position ofa blockage are detected in response to this displacement. Therefore, itis possible to provide a coordinate-position input device enablingaccurate reading of written contents by correcting this displacementwith simpler structure and accurately detecting coordinate values of theposition of the blockage.

In the present invention, the configuration thereof can be simplified bysharing a reading element and a light detecting unit to suppress anincrease in the number of components. Therefore, load to maintenance ofthe device and chances of failure can be reduced and further cost of thedevice can be suppressed.

In the present invention, one of the inventions described above can beapplied to a display board system. Thus, a display board system can beconstructed using the coordinate-position input device with a lightreceiving section and a light source attachable thereto with highprecision. Therefore, so that it is possible to provide a display boardsystem enabling detection of written contents with high precision. Inaddition, the display board system can be constructed using thecoordinate-position input device enabling accurate reading of writtencontents by accurately computing displacement in an attached angle andcorrecting this displacement more easily, so that it is possible toprovide a high-reliability display board system.

Although the invention has been described with respect to a specificembodiment for a complete and clear disclosure, the appended claims arenot to be thus limited but are to be construed as embodying allmodifications and alternative constructions that may occur to oneskilled in the art which fairly fall within the basic teaching hereinset forth.

What is claimed is:
 1. A system, comprising: a device having a frontwriting surface and a back portion, the device being rigid; a supportconnected to the device; a frame configured to be attached to thedevice; a bracket attached to only one side of the frame withoutsurrounding the frame and configured to prevent the frame from beingremoved from the device due to contact between the bracket and the backportion; a light source connected to the frame; and a light sensorconnected to the frame.
 2. A system according to claim 1, furthercomprising: a coordinate-position identifier, wherein the light sourceand the light sensor are electrically connected to thecoordinate-position identifier.
 3. The system of claim 2, furthercomprising: an interface section connected to the coordinate-positionidentifier; and a personal computer and a printer connected to theinterface section.
 4. A system according to claim 1, wherein: thebracket removably attaches the frame to the device.
 5. The system ofclaim 1, wherein the device is a white board.
 6. The system of claim 1,wherein the device is a plasma display.
 7. The system of claim 1,wherein the light sensor includes: a charge coupled device (“CCD”)sensor.
 8. The system of claim 1, wherein the bracket comprises: a hook.9. The system according to claim 1, wherein: the bracket rests on thedevice.
 10. A system according to claim 1, wherein the system isfree-standing.
 11. A system, comprising: a writing surface connected toa rigid back portion; a support connected to the back portion; a frameconfigured to be mounted proximate to the writing surface; a bracketattached to only one side of the frame without surrounding the frame andconfigured to prevent the frame from being removed from a proximity ofthe writing surface due to contact between the bracket and the backportion; a light source connected to the frame; and a light sensorconnected to the frame.
 12. A system according to claim 11, furthercomprising: a coordinate-position identifier, wherein the light sourceand the light sensor are electrically connected to thecoordinate-position identifier.
 13. The system of claim 12, furthercomprising: an interface section connected to the coordinate-positionidentifier; and a personal computer and a printer connected to theinterface section.
 14. A system according to claim 11, wherein: thebracket removably attaches the frame to the writing surface.
 15. Thesystem of claim 11, further comprising: a white board which includes thewriting surface and the back portion.
 16. The system of claim 11,further comprising: a plasma display which includes the writing surfaceand the back portion.
 17. The system of claim 11, wherein the lightsensor includes: a charge coupled device (“CCD”) sensor.
 18. The systemof claim 11, wherein the bracket comprises: a hook.
 19. The systemaccording to claim 11, further comprising: a device including thewriting surface and the back portion, wherein: the bracket rests on thedevice.
 20. A system according to claim 11, wherein the system isfree-standing.
 21. A system, comprising: a device having a front writingsurface and a rigid back portion; a frame configured to be attached tothe device; a bracket attached to only one side of the frame withoutsurrounding the frame and configured to prevent the frame from beingremoved from the device due to contact between the bracket and the rigidback portion; a light source connected to the frame; and a light sensorconnected to the frame.
 22. A system according to claim 21, wherein: thebracket is arranged to contact the back portion of the device.
 23. Asystem according to claim 22, wherein: a contact between the bracket andthe back portion of the device prevents the frame from being removedfrom the device.
 24. A system according to claim 22, wherein: thebracket rests on the device.
 25. A system according to claim 23,wherein: the bracket rests on the device.
 26. A system according toclaim 21, further comprising: a coordinate-position identifier, whereinthe light source and the light sensor are electrically connected to thecoordinate-position identifier.
 27. The system of claim 26, furthercomprising: an interface section connected to the coordinate-positionidentifier; and a personal computer and a printer connected to theinterface section.
 28. A system according to claim 22, wherein: thebracket removably attaches the frame to the device.
 29. The system ofclaim 22, wherein the device is a white board.
 30. The system of claim22, wherein the device is a plasma display.
 31. The system of claim 22,wherein the light sensor includes: a charge coupled device (“CCD”)sensor.
 32. The system claim 22, wherein the bracket comprises: a hook.33. A system according to claim 21, wherein the system is free-standing.34. A system, comprising: means for receiving writing by a personincluding a front writing surface and a rigid back portion; means forsupporting the means for receiving; means for framing the front writingsurface; means, attached to only one side of the means for framingwithout surrounding the means for framing, for preventing the means forframing from being removed from the means for receiving due to contactbetween the means for preventing and the back portion; means forilluminating, connected to the means for framing; and means for sensinglight, connected to the means for framing.
 35. A system according toclaim 34, further comprising: means for identifying a coordinateposition, wherein the means for illuminating and the means for sensinglight are electrically connected to the coordinate-position identifier.36. The system of claim 35, wherein: the means for identifying comprisesa personal computer.
 37. A system according to claim 34, wherein: themeans for preventing removably attaches the frame to the device.
 38. Thesystem of claim 34, wherein the means for receiving writing comprises: awhite board.
 39. The system of claim 34, wherein the means for receivingwriting comprises: a plasma display.
 40. The system of claim 34, whereinthe means for sensing light comprises: a charge coupled device.
 41. Thesystem of claim 34, wherein the means for preventing comprises: a hook.42. A system according to claim 34, the system is free-standing.
 43. Amethod, comprising the steps of: contacting a frame to a device having afront writing surface and a rigid back portion the frame connected to alight source and a light sensor; and arranging a bracket which isattached to only one side of the frame without surrounding the frame, toprevent the frame from losing contact with the device.
 44. A methodaccording to claim 43, further comprising the step of: sensing aposition using the light source and the light sensor.
 45. A methodaccording to claim 43, wherein the frame is free-standing.
 46. A system,comprising: a device having a front writing surface and a back portion,the device being rigid; a support connected to the device; a framehaving four corner portions and configured to be attached to the device;a bracket attached to the frame and configured to prevent the frame frombeing removed from the device due to contact between the bracket and theback portion; and an integrated optical unit having a light source and alight sensor, the integrated optical unit being detachably connected toany of the four corner portions of the frame.